An In-Line Microwave Power Detection System Based on Double MEMS Cantilever Beams

An in-line microwave power detection system based on double MEMS cantilever beams is proposed in this work. It realizes the separation of power sense and power detection. A 10% coupling factor can be achieved with the double cantilever beams, and the performance of this in-line microwave power detection system based on double cantilever beams is improved compared with the single beam. The in-line microwave power detection system is designed and fabricated using GaAs MMIC process and MEMS technology. The theoretical models of cantilever beam with different structures are also established and verified. The relationship of return loss, insertion loss and coupling coefficient with the frequency and the capacitance are studied. The measurement results show the return loss is from -9.3dB to -17.7dB, and the insertion loss is from -2.9dB to -1.9dB at 9-11 GHz. The sensitivity of the in-line microwave power detection system is around 1.1 mV/W, 1.45 mV/W, 0.85 mV/W at 9, 10, 11 GHz, respectively. Therefore, this in-line type microwave power detection system can effectively detect microwave power with a high reliability.